Easter 2025 is almost three weeks later than it was in 2024, taking place on Sunday, 20th April. This is a common occurrence for the holiday, with each year providing a different March or April date to celebrate.
You’re probably wondering why there’s such a difference and how Easter can have such flexible dates compared to other holidays.
Here at Sky HISTORY, we’re going to be diving deeper into this topic. Join us as we examine the origins of the Easter holiday and determine why the dates are ever changing, as well as how the moon is involved.
What date is the Easter holiday season?
As mentioned, there is no set date for Easter, which is why the date can change every year. However, there is a certain time frame in which the holiday takes place.
Easter can occur on any Sunday between 22nd March and 25th April. It’s taking place on 20th April in 2025, but the latest date it took place in recent years was on 21st April 2019. This late April date will not occur again until 2038.
This everchanging nature has led to the holidays that lead up to the Sunday event – such as Good Friday and Ash Wednesday – to be referred to as 'moveable feasts'.
How is the date of Easter calculated?
Easter is determined via astronomical calculations that combine the lunar and solar calendars. This system dates way back to the very early years of Christianity.
The Sunday that Easter falls on is usually the first Sunday that follows the Paschal Full Moon. This is the first full moon that occurs either on the day of or after 21st March. This is a fixed date that approximates the spring equinox within church traditions, hence why it is used.
The Paschal Full Moon is not a full moon that is astronomically accurate. Instead, it is a moon that is based on church created ecclesiastical tables. These tables don’t utilise direct observations of astronomy. They offer a more simplified version of the moon’s cycle.
This method might not be in line with actual astronomy, but it allows for independence from the Earth’s longitude and time zones. This also means that Easter's date can be calculated in advance, no matter what the motion of the Earth around the Sun might be.
When was this system created?
The origins of the system used to determine the date of Easter go back to the year 325 AD. A decree written by the Council of Nicaea within the early Christian church established this method. Before this date, there was no agreed-upon method for determining when the date of Easter would fall.
Modifications came to be when the Gregorian calendar was adopted. The solar-based Gregorian calendar did not perfectly align with the lunar calendar, leading to the variability of the Easter date.
The difference between Eastern churches and Western churches
There is a difference when it comes to the dates of Easter in Western and Eastern churches. These differences come from the use of different calendars.
The Gregorian calendar is used by Western churches and was established in 1582 by Pope Gregory XIII. As mentioned, the calendar utilises ecclesiastical calculations to figure out the date of the Paschal Full Moon. Eastern churches use the Julian calendar. This is a solar calendar that is 13 days behind the Gregorian calendar and was adopted in 45 BC by Julius Caesar.
A similarity between Western and Eastern churches is that they both determine that the date of Easter comes after the Paschal Full Moon. However, Eastern churches insist that the date has to be after the Jewish Passover holiday so that historical continuity is maintained in regards to the Crucifixion and Resurrection timeline. Because of this, Orthodox Easter is often later than Western Easter.
The dates of Easter are a fascinating topic, reflecting the history of Christianity as well as historical traditions and elements of astronomical patterns. So, if you’re wondering why Easter is so late this year, you now know that the moon is partially to blame!
Want to stay up to date on a range of historical topics? Then make sure to subscribe to the Sky HISTORY newsletter! You’ll get exclusive access to all the latest Sky HISTORY content as well as notifications of brand new articles, videos, and other content.
